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chris98zjV8

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Discussion starter · #1 ·
Hey just to get some input from everyone, Ive been doing some research about turbo diesel engine swaps for the zj. I have ran across a few 4bt (3.9l) swaps that went well and are working great. There is one i ran across that is a 95 zj with 7" long arms and a 4bt and 315 75 16's and hes getting 28mpg. Ive also ran across a 4bt that was making 320 hp and 590 tq so he claims... Not sure but its almost seems like a no brainer if you can make that kind of power and get awesome fuel economy. Has anyone done this swap on here??
 
You mean the Green ZJ that had the 4BT in it (being in VA, you may have seen it at Big Dogs?). It was a 98.

Anyways, he has since parted out and scrapped it. It was a cool swap and everything. He got great mileage. It definitely performed as expected, but he just got frustrated with how loud it was inside the rig. It crawled amazingly, but he hated it in the mud and other climbs because of its weight and lack of wheel speed on demand. He also got sick of getting hassled about it everywhere he went (Hey! Does that thing have a diesel?).
 
Discussion starter · #4 ·
I'm trying to figure out what exactly I need to get. I haven't found a kit for a zj swap like other jeeps... So I need to find out exactly what parts I need, from fuel system to electronics...(hopefully I can get rid of some). Also what the rest of my drivetrain will consist of.
 
Discussion starter · #5 ·
You mean the Green ZJ that had the 4BT in it (being in VA, you may have seen it at Big Dogs?). It was a 98.

Anyways, he has since parted out and scrapped it. It was a cool swap and everything. He got great mileage. It definitely performed as expected, but he just got frustrated with how loud it was inside the rig. It crawled amazingly, but he hated it in the mud and other climbs because of its weight and lack of wheel speed on demand. He also got sick of getting hassled about it everywhere he went (Hey! Does that thing have a diesel?).
Yeah I think I'm going to step up the sound deadening material inside and out! Also a good but not restrictive resonater to cut some of the sound down. You have any contact info for this guy? I have a few questions to ask.
 
I've been thinking about doing a 4BT in my ZJ for 2 years. I read alot of good info on 4bt.com.
Here is one of the ZJ's on the site.
Also, you may want to look into Lizard Skin. It'll help with the sound deadening.

I still may go this route down the road, but I'm going to build a stroker first and see how I like it.

Hope that info helps you out!
 
sound deadening...if you rode in one of my work's old Detroit powered Volvo's, I bet a 4bt-powered ZJ would sound like a smart car in comparison....
 
Discussion starter · #9 ·
I'm going to start putting a list of all parts needed for the swap for me and everyone else who wants them. I have to do some more research when I get the time to make sure I don't forget any vital components. I'm really interested in this swap because of life expectancy for the motor and fuel milage. A guy I work with is telling me 500,000 miles is not out of the question with routine maintence. I'm looking to keep my zj for a LONG time so I can benefit for sure with a swap like this. Any input on parts or anything will be helpful with putting this swap into action...
 
So, what is this 4BT engine, a 3 cylinder cat engine ??
whats the cost of this engine ?? just looking
 
Sorry dont answer that, I just found them on ebay
 
The 4bt is a 4 cylinder, 3.9 liter cummins engine. One of the more common places to get one is buy a p30 van off the website www.dovebid.com and part out/scrap the van, keeping the engine.
The 3.9 is basically a 5.9 cummins minus 2 cylinder, and as such, alot of the performance stuff will work on a 3.9
 
me too

i also was thinking about this swap for my 04 grand cherokee or doing a 4.7L stroker. but would rather do the 4BT swap for gas mileage. will be keeping an eye on this thread


I am kicking around the stroker idea too. The 4.2 crank and rods then new pistons. Not to jack the thread.



I had thought about the 4bt cummins too. Had a lot of info about them in xjs, so doing the swap in the zj should not be to far off.
 
There was one done in an orange TJ a couple of issues back in CRAWL magazine. I went out with them a bit when they were shooting it for the magazine. I'm not exactly sure what the guy had done, but he was able to take a considerable amount of vibration and noise out of the equation in his. I think alot of it had to do with motor mounts.
 
The 4bt are very easy to maintain (so long as the oil is changed evry 5k) and work on as there is only the wires for the alternator and starter and 1 wire for the fuel shut off selenoid as well as one wire for the preheater very easy simple design and yes its not uncommon to get over 500k out of one of these engines. Isuzu makes a 4bt also that is almost identical and will bolt up to chevy trannys with an adapter these are also found in bread trucks. The newer 4bts both cummins and isuzu have electronic fuel control so stay away from them if you want a simple swap otherwise you will need to wire in the computer that runs them. Good luck and keep us posted
 
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